A my K ind being in the state of c-fiber firing Functionalism manages to block both of these threats by treating mental states as functional states For the functionalist, a mental state like pain is identified by the functional role that it plays in the life of the organism While historical antecedents to functionalism can be found in the work of Aristotle and Hobbes, the view received its first detailed development in the second half of the 20th century.14 Its rise coincides with important developments in computer science and particularly in artificial intelligence, and functionalists have often drawn on computational analogies in spelling out their position On the functionalist view, mentality is better thought of at the level of software than at the level of hardware 3.1 Mental states as functional states Above we noted that a device like a mousetrap can be realized in multiple different physical structures For something to be a mousetrap, what matters is not what it is made of but what it does, i.e., the function it performs The notion mousetrap must thus be specified not physically but functionally In this way mousetraps are different from, say, nuggets of gold For something to be a gold nugget, it must have a specific physical constitution, i.e., it must be composed of atoms with atomic number 79 – hence the truth of the expression, “All that glitters is not gold.” Compare pyrite, or fool’s gold, which has a similarly brilliant yellow luster but is a compound of iron sulfide Mousetraps are not the only things that are specified functionally A similar point applies to many other artifact concepts – engines, clocks, pencil sharpeners – and even biological concepts As Jaegwon Kim notes, What makes an organ a heart is the fact that it pumps blood The human heart may be physically very unlike hearts in, say, reptiles or birds, but they all count as hearts because of the job they in the organisms in which they are found, not on account of their similarity in shape, size, or material constitution (Kim 2011, 131) The functionalist claims that mental states are better understood on the model of the mousetrap than on the model of gold nuggets Consider again the mental state pain This state plays a certain role in the life of an organism It typically comes about because of bodily damage, and it typically results in wincing, moaning, avoidance behavior, fear, a desire for relief, and so on Or consider the mental state thirst It typically comes about because of lack of adequate hydration, and it typically results in dry mouth, liquid-seeking behavior, a desire for liquids, and so on As this suggests, the functionalist’s characterization of mental states is strikingly reminiscent of the behaviorist characterizations of mental states In particular, both the functionalist and the behaviorist define mental states in terms of a relation between inputs and outputs But despite this similarity, there are nonetheless 64